Clinical code lists – Asthma, Eczema and Hay fever

CTV3 Read codes and British National Formulary (BNF) codes were used to define cases of asthma, eczema and hay fever using electronic primary care records in the Born in Bradford birth cohort. CTV3 (Clinical Terms Version 3) Read codes are coded clinical terms designed for use in electronic health records in the NHS in the UK and BNF codes are for prescriptions of medications. This was part of a project to investigate the association between in-utero antibiotic exposure in babies born by caesarean section and subsequent risk of allergic disease and asthma in the Born in Bradford birth cohort